Toucam time delay

Although it isn't an astronomy issue, someone may be able to give an answer:
what is the reason for the time delay of a ToUcam (II Pro) when used as a
real time camera? The delay on my system is about 0.25 seconds, independent
of stream format parameters such as output size (160x120 upto 640x480) and
frame rate. I am using the VRecord program.

On Fri, 10 Mar 2006 20:35:43 -0000, jkien wrote:

Although it isn't an astronomy issue, someone may be able to give an
answer:
what is the reason for the time delay of a ToUcam (II Pro) when used as a
real time camera? The delay on my system is about 0.25 seconds,
independent
of stream format parameters such as output size (160x120 upto 640x480)
and
frame rate. I am using the VRecord program.




The combination of time taken sending over USB, storing in RAM, buffering
and per-frame display on the screen would equate to a near-constant delay.

"jkien" wrote in message
...
Although it isn't an astronomy issue, someone may be able to give an
answer:
what is the reason for the time delay of a ToUcam (II Pro) when used as a
real time camera? The delay on my system is about 0.25 seconds,
independent
of stream format parameters such as output size (160x120 upto 640x480) and
frame rate. I am using the VRecord program.


While some delay is probably unavoidable, K3CCDTools will at least give you
the timing of frames to within 50ms - See
http://www.pk3.org/Astro/k3ccdtools_whats_new_2_1_2.htm

Robin

"Jonathan Bell" wrote in message
news
On Fri, 10 Mar 2006 20:35:43 -0000, jkien wrote:

Although it isn't an astronomy issue, someone may be able to give an
answer:
what is the reason for the time delay of a ToUcam (II Pro) when used
as a real time camera? The delay on my system is about 0.25 seconds,
independent
of stream format parameters such as output size (160x120 upto
640x480) and
frame rate. I am using the VRecord program.




The combination of time taken sending over USB, storing in RAM,
buffering and per-frame display on the screen would equate to a
near-constant delay.


Ah, I wasn't aware that automatic frame rate control was enabled by default,
and the imaged object was a bit dark, so each time after I set the (initial)
frame rate to a value in the range 5 - 60 fps, it silently changed to about
10 fps after a few seconds. Consequently the real-time imaging delay
increased to about 0.3 seconds. The delay is actually dependent on frame
rate, after all. At a frame rate of 30-60 fps (and automic frame rate
disabled), the delay is 0.2 seconds or less.